Pakistani nuclear scientist Abdul Qadeer Khan, who sold nuclear secrets to Iran and Libya, had commercial contacts with at least 20 different countries and large companies, Director General of the International Atomic Energy Agency Mohammed El Baradei said.

Hinting at a broader involvement, the top nuclear cop said "this work could not be the work of Khan alone. The IAEA only learned about some of his activities 18 months ago when Khan's contacts with Libya came to light. The Americans and others had, however, been tracking Pakistani's contacts for some time before that."

Asked why the IAEA does not reveal the names of those countries that helped Iran in their nuclear acquisition efforts, such as China or Pakistan, El Baradei told the Israeli daily Ha'artez that the IAEA will need those countries' cooperation in the future.

In view of the changed scenario when terror is getting more sophisticated and other countries could get nuclear weapons, El Baradei said the ordinary deterrence that worked in the past may not be effective any more and Israel must think about a different regional security concept and lend a hand to it.

On a two-day visit to Israel at the invitation of the Israel Atomic Energy Commission, the IAEA head, has said that he understands Israel's security concerns where there is a "very strong sense of existential threat" and therefore he suggests the creation of a "nuclear free zone" in the Middle East.